Today, computer systems include many electronic components that include integrated circuit devices and/or multi-chip modules. These integrated circuit chips may include at least one central processing unit. Newer versions of integrated circuits, such as the CPUs, are often faster, yet require more power; even so, newer electronic components are often most desired.
Many electronic components generate heat as a result of their use. The amount of heat that is generated by these components may cause harm to other components in the computer system. Therefore, computer systems typically include some mechanism to dissipate the heat produced by these electronic components, thereby protecting those components which may be damaged by such heat. In desktop and mainframe computer systems, fans are often included to help dissipate the heat generated by these electronic components. Also, heat sinks may be attached to selected electronic components to help dissipate heat by spreading out the heat over a larger surface. Although the heat sinks and fans may be used to cool larger systems, they are not always effective in dissipating heat generated in notebook or portable type computers. This is because the small form factor associated with notebook computers makes it difficult to include the components while maintaining its small size. Furthermore, users often do not like the vibration and noise associated with a fan.
Another problem that may be associated with dissipating heat in notebook computers that may be attributed to the small form factor is that heat can be concentrated at certain spots of the external casing of the notebook computer. These "hot spots" on the external skin may be uncomfortable to the touch and may cause injury. Therefore, for heat dissipation in notebook computers, it is desirable to dissipate the heat in such a way so as to avoid creating hot spots.
One solution in the prior art to dissipating heat in a portable computer is described in U.S. Pat. No. 4,980,848, entitled "Heat-Exchange Panel for Portable Computer", issued Dec. 25, 1990. A computer system is described having a lid that includes a central processing unit (CPU) mounted behind an LCD visual display. The front of the display provides support for circuit boards in a spaced-parallel relationship to the LCD screen and the rear cover. When the lid is open, air flows by convection through lower vent holes in the cover, over both sides of the board containing the CPU, and exits through upper vent holes in the lid. Two problems associated with the lid assembly is that the space available for passive venting of air through the lid assembly does not provide significant heat transfer and increases the overall dimensions of the portable computer. The inclusion of this added space is in direct conflict with desires to reduce the size of portable computers while only providing very limited transfer of heat from the electronics to the ambient surrounding environment. Furthermore, in such an arrangement, there is no adequate protection to the LCD display from the heat that is generated by the components in the circuit boards contained within the lid.
Thus, a need exists to provide a heat dissipation/cooling system for notebook computers that is very efficient, yet provides only a minimal increase the overall size of the notebook, or portable, computer.